Why do batteries just quit?

Seems like years ago when a battery got bad it gave you warning signs and you knew it was failing.

In the last few years I have had several cases where the battery was fine one minute and the next time...nothing.
It even happened once while I was at an auto parts store. I went in to get some items, came out and the truck would not start. Battery had failed.....but a convenient place to do it. Another time I was ready to bale and rushing to beat the rain, went to the baler tractor....dead.

In some cases they won't even jump. It is especially frustrating (and potentially dangerous) when it happens to your wife, away from home and at night.

Any thoughts on this? Any way to see it coming.

I thought a had a battery going bad in my truck till I figured out if I unplugged the trailer brake controller it would work just fine. So now when I park it I unplug the controller and it has been fine for well over a year. Little things count so it is good to check for any thing that will cause a draw.

A slow gradual decline (normal aging) in battery performance can be due to sulfation on the plates rendering them less and less efficient over time. A sudden catastrophic failure (among other things) can be due to an internal short such as accumulation in the bottom getting so deep it creates a short across the cells, or perhaps severe vibration can result in plate failure. A new battery can have a rating of X number of "Life Cycles" being roughly how many times its discharged then recharged, so the more its kept at or near 100% SOC the better. I'm my RV I don't like to discharge my house batteries much over 20% to 30% down.

Hope this helps , there's MUCH more but that's good enough for now I hope. I'm sure the other fine gents can add to this.

John T

A battery is just a box with a bunch of battery cells wired together in series. Those cells can all degrade slowly - or - you can get a bad connection between one of them. If a bad connection - it just goes DEAD, just like that.

Owned a Dodge Durango a few years ago. Started it up, drove to the local Case-IH dealer, did some business, then went to the farm store. After that we went uptown for breakfast. Came back out and the battery was completely dead. It had enough to unlock the doors, and then nothing. Called the dealer. He brought a jump-pack. That didn't work. He went back and got a brand new battery, and that fixed it. Durango was less than one year old at the time.

USED TO.... as the battery deteriorated, the engine would crank slower or even studder and you had warning of impending failures..


TODAY.. the computer monitors the battey voltage while cranking, and if it drops below 9volts cranking, it just refuses to even let the car try to crank... no slow cranking, no studder, just a click and no crank as the computer will not allow it to happen as it cannot set timing or idle or anything else with low voltage, so its program to not even try if the voltage drops.

SO.. bottom line,, newer cars will experience the sudden 'NOTHING" symptoms by design.

Yes there is still shorting cells or open cell failures vs the sulfation of the plates.. but now.. who can tell.. it just does NOT crank.... only a test of the battery after its pulled out will tell you what happened, but who cares, if a new battery fixed the problem, you just move on.

Great explanation, thx.
Unfortunately, still does not give me a warning that my wife's car battery is going bad.

But your info makes a lot of sense.

(quoted from post at 08:46:04 04/30/17) Great explanation, thx.
Unfortunately, still does not give me a warning that my wife's car battery is going bad.

But your info makes a lot of sense.

Click to expand...

Yes, it does make sense, but still doesn't explain why a vehicle that is less than one year old, and started easily 4 times in a row, suddenly was stone cold dead.

I was about to mention something like the brake controller. Anything built in the last few years has a constant battery drain when not being used. The only way to keep that from happening is to put a battery switch on it. That creates another set of problems. My 2001 Dodge pickup doesn't care, but I have a 1996 Chevy Lumina that will drive like it's going to come apart if the battery is disconnected and hooked back up. It has to "relearn" stuff.

I have had vehicles that would drain a battery in a week of non use. Had a 1990 Cougar like that. Drive it every day and things were fine. Park it for a couple of weeks and it had to be boosted. Never really found the leakage if there was some. We had a Dodge mini van that belonged to where I work. Kept it parked in the warehouse when not being used. It could sit there for a month and start up just fine.

Bottom line: No solutions. I think batteries are better in some sense, they have more cranking amps, but the quality of the build is way down. You aren't going to get much more than three or four years out of any of them. There are exceptions, but I question the guy who says his battery is 7 years old and has never given any problems. The longest I ever had one last was on a 61 Plymouth my parents bought new. That battery was 12 years old when it died. Weighed a ton and cost a lot to replace too.

Alot of it has to do with the constant heat surrounding the battery, Most vehicles now have the battery stuffed down between the fender and the engine. It lives in a 200+ degree environment,basically getting cooked as long as the engine is running.Along with that it has a severe electrical drain due to all the ecms,computers,and electrical options the vehicle has, then add in the 120-160 amp alternator trying to keep it charged. Sooner than later something has to give and it is usually the battery.

Connection between the cells inside the battery can result in full power and then no power. Just like can
happen with a bad connection outside the battery box.

I wonder too if the battery being exposed to heat makes a big difference. I sold my 2004 Saturn last fall and the original battery was still going strong. It's battery was located in the trunk instead of the engine compartment.

Unfortunately, grrrrrrrrrrrr a short or broken internal connection can cause that instantly regardless if it ran fine prior.

John T

It's a conspiracy I tell ya. About the last 4 batteries I've had in numerous vehicles dropped dead within several weeks to the year rating of their purchase date. 5 year battery; 4 years 50 weeks, 3 year battery 3 years 1 week, etc. I think there is an internal timer, installed by the company so it knows when to shut off.

I had a battery pop on me coming out of Menards lot. I had to shut engine off and open the hatch for the employee to check out my purchase. Got in, turned key, and literally, it made a pop. It was so dead that rolling down the hill, stick shift, it would not fire.
A jump start got it going and drove across the street to Runnings and put in a new battery. I would have loved to tear that battery apart but of course had core value.

Daughter and son in law go to Hawaii for two weeks. Come home and car is dead a door nail. He jumps it, drives for about 20 minutes and says seems ok now. I told him he would need to drive to the west coast to get it fully charged because once that initial charge the alternater pushes in, that battery will push back and only a small charge will continue. I don't think he believed me.

I told him he needed to hook a slow charger on and leave it on for a day or so if he had a chance of getting it back to full charge. Told him, do not buy one of those automatic chargers as it will just shut off in a hour or so because that battery will push back (counter electromotive force) and fool the charger. Well, he ended up with a automatic and it charged for less than two hours and shut off.

He was down here about a week later, 240 mile drive, and I was tying to explain things to him. Fully charged battery will read 12.6 after standing over night. Near dead will show maybe 12 volts. So, we went out in the morning and I put my load tester on. I did not apply any load as it showed just under 12 volts. I said I don't dare load test or I will run it dead. Then I hooked load tester to my pickup. That battery is 7 years old now and I was suspecting it might be getting a little tired. It did not show a full 12.6 either. Only 12.4. Load tested ok but not quite as good as I would expect for a good battery that size.

They are still driving on that battery , but I will bet if they let it sit for a couple of days, it will be dead again. I don't know how much draw all the gadgets the car has but in four years of stop and go, short trip to work driving, I would say that battery has never had a chance to fulfill it's manufactured potential. It just never gets up to full charge so it gradually loses it's capacity.

"They are still driving on that battery , but I will bet if they let it sit for a couple of days, it will be dead again"

False economy trying to keep a battery that's starting to go. A bad battery will also kill the alternator.

It isn't hurting the alternator as because as soon as it starts the car, the alternator settles right out with low amp output at a normal regulated voltage. The battery is just going to let them sit one of these days.

I have had two batteries die suddenly in my Jeeps. Last summer I bought a new battery from NAPA for my tractor. I put it in and it would not turn the engine over so I charged it for a hour and it was still dead. I took it back to NAPA and they said that was impossible the battery would not charge. They tried and failed to charge it. I also had it happen with a battery from Advance Auto parts.

As I recall, most automotive jars have six cells in them, each putting out somewhere around 2.17 VDC (nominal) x six cells. The individual cell voltages can be higher or lower than that. A jar has to complete a circuit across the six cells between the positive and negative terminals. Something opens in any one of the cells or from either terminal to the last cells in the jar, or a short across two of the plates in any of the cells...and its over. Sure jars can and do weaken over time across the cells as the plates scale or whatever, but on occasion jars have always been known to and sometimes will just go dead depending on the failure. Compare it to a light bulb going out when the filament suddenly opens and fails to complete its electrical circuit. You go to bed and shut off a perfectly good working light bulb, get up and attempt to turn the same light bulb on...and nothing happens until you change out the now bad bulb.

Mark

(quoted from post at 09:49:00 04/30/17)

(quoted from post at 08:46:04 04/30/17) Great explanation, thx.
Unfortunately, still does not give me a warning that my wife's car battery is going bad.

But your info makes a lot of sense.

Click to expand...

Yes, it does make sense, but still doesn't explain why a vehicle that is less than one year old, and started easily 4 times in a row, suddenly was stone cold dead.

Click to expand...

The CAR may have been a year old but how old was the BATTERY? It could have been manufactured a long time BEFORE it was put into the car.

(quoted from post at 20:15:53 04/30/17)

(quoted from post at 09:49:00 04/30/17)

(quoted from post at 08:46:04 04/30/17) Great explanation, thx.
Unfortunately, still does not give me a warning that my wife's car battery is going bad.

But your info makes a lot of sense.

Click to expand...

Yes, it does make sense, but still doesn't explain why a vehicle that is less than one year old, and started easily 4 times in a row, suddenly was stone cold dead.

Click to expand...

The CAR may have been a year old but how old was the BATTERY? It could have been manufactured a long time BEFORE it was put into the car.

Click to expand...

You mean something like 2 to 3 days before?